Yeah, I was considering the 5770 instead of the 4890 but I have seen the 4890 outperform the 5770. I was also considering the 5850 but it is not available anywhere and would like to have this system built now.
Do you think the 5770 is a better deal instead of the 4890? What are the advantages?
The advantage of the 5770 is DX11, thats all. In a couple years the 5770 will still run new games in DX11 on a 22 inch 1380x1050 LCD monitor at high graphics levels. The 4890 will never run DX11. (Like being stuck at DX9 now with all the DX10 games available). Its a short vs long term decision.
The Phenom II is a bit faster that the Athlon II. If your software isnt going to use all 4 cores effectively then the fewer faster cores will get you better performance. Also the Ph2 720 will overclock easier and might even let you unlock its 4th core to have a totally superior CPU at the same price.
As long as it has front, top and rear fans you should be fine. Side fans are an extra benefit.